The Ontario Building Code | Framing around Openings
9.23.13.2. Framing around Openings
(1) Roof and ceiling framing members shall be doubled on each side of openings greater than two rafter or joist spacings wide.
In Plain Language
Framing around openings in a roof or floor, such as for a skylight or stairwell, must meet the requirements set out in this article.
This is a plain-language summary of the 2012/2017 Ontario Building Code text above, for general understanding only and not a substitute for the Code. Always confirm current requirements against the 2024 edition (O.Reg. 163/24) or a qualified professional before construction.